Asterisk setup success 6

I was hired to install a PBX for a medium sized company. The CEO's main concern was not using proprietary cards that could fail or not be supported in the future. The second requirement was to have the system available during hardware failure and power outages.

I replaced an Altigen System that had a bank of ISA cards. These cards were slowly going bad, losing quality, or just not doing anything. Some users still had voice mail on the old system so I had to have the old voice mail available for a few weeks after the switch.

Hardware failure is worked around by using two servers on the same switch. Ucarp runs between the two servers. System configuration and voice mail gets backed up to fail over server. When the master server stops sending Ucarp packets, the fail over server starts running commands. IP phones point to a floating IP address that is docked at the master. When fail over occurs the second server assumes the floating IP, reboots the phones, then starts the Asterisk daemon. During hardware failure on the first server, the second server is running in six seconds.

Fail over is useful in the event of hardware or power failure. If the power goes out, the first server stays on line while the second server powers down. When the first UPS signals a low batter, the second server comes back on line and takes over. Effectively doubling run time.

The old system was wired into a stereo receiver for over head paging. I had to create a low cost way to use the paging system. My first thought was to make calls into the console and plug the PA into the sound card. The servers I received didn't have sound cards. I needed the fail over to have the PA as well. I ended up with a hardware hack on a Budgetone 100 that auto answered. Basically I soldered an RCA connector to the speaker wire. Problem solved.

Since I had a 24 FXO channel bank and only eleven POTS lines, I wired one port into the old PBX. Dialing an extension on the Asterisk system sent a call to the old PBX where a user could re-check their old voice mail. Since then I've completely disabled the old PBX. Asterisk has been going rock solid for a month now.

The phones are all wired back to a server room. I'm using D-Link PoE switches to power the 50 phones. Redfone hardware came with it's own PoE injector that was handy to use. The phone network is completely isolated from the computer network, and there's only one wire running to each phone. Similar to normal office phones. The difference is higher sound quality and more features. Asterisk works 100% in production.


  • Super Micro AMD64
  • AMD64 4000+ CPU
  • 4 Gigs of non ECC ram
  • 80 Gb SATA hard drive
  • two server fail over using UCARP
  • 50 Grandstream GXP 2000 VoIP phones.
  • 1 Grandsteam Budgetone 100 hardware hacked for over head paging.
  • Rhyno Channel Bank with 24 FXO (for future expansion).
  • Redfone 4 T1 to TDMoE bridge. (for more expansion)
  • 2 Belkin 1100V UPS'
  • 11 POTS lines from Telephone Company.
  • 10 Grandstream 286 ATA's to use as needed
  • Phones are on a separate switched network with PoE

Special features in Extensions rule set with Asterisk

  • Conference Calls
  • Overhead Paging
  • MP3 Music on Hold
  • Voicemail
  • Company Directory by first or last name
  • Searchable MySQL database for incoming CID

Overall experience:
The owner of Redfone was eager to provide TDMoE tips (try fxs_ls). The GXP2000 phones were giving me problems at first. I gave Grandstream a few calls and ended up with the 1.2.3 firmware. New phones ship with 1.2.3 firmware. They're working pretty well. I have call waiting turned off because I had weirdness when a call came in after someone was already on the phone. This problem was solved. Other then that, a few phones fell off people's desks, but everything is fine.

If you'd like to discuss this system feel free to call my PBX at (707) 703-1982 extension 264

Created by: cwidger, Last modification: Mon 08 of Dec, 2008 (23:48 UTC) by wl7aml
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